CN202134793U - A semiconductor laser - Google Patents

Abstract

The utility model discloses a semiconductor laser, which includes a main light source, a temperature control system, an optical shaping system and a power control system; the fiber-coupled semiconductor laser is fixed on the cold surface of a semiconductor refrigerator, and the hot surface of the semiconductor refrigerator is connected to a base; The fiber output end of the fiber-coupled semiconductor laser is equipped with an end cap; the end cap is connected with the collimator lens; the collimator lens is fixed on a V-shaped groove, and a beam splitter is arranged on the output optical path of the collimator lens, and the beam splitter of the beam splitter A photodiode is installed on the optical path, and the photogenerated current of the photodiode is used as a control signal and connected to a feedback control system. The semiconductor laser of the utility model has high beam quality, high stability, long life, small volume, light weight and low cost.

Description

A semiconductor laser

technical field

The utility model relates to the field of semiconductor lasers, in particular to a free space output semiconductor laser.

Background technique

In recent years, with the development of optoelectronic technology, semiconductor lasers have been used more and more widely. They have high photoelectric conversion efficiency, wide coverage wavelength range, long service life, high-speed modulation, small size, light weight, and cheap price. features. However, due to its light-emitting mechanism, the beam quality of semiconductor lasers is poor, and its output is often accompanied by strong stray light; the light-emitting points in the two directions are different, resulting in phase dispersion; the transverse mode characteristics are not ideal. These shortcomings severely limit the application of semiconductor lasers, especially in the fields of cell analysis, virus detection, and semiconductor detection.

In order to solve the problem of poor beam quality of semiconductor lasers, fiber-coupled semiconductor lasers have been developed. The output beam of the semiconductor laser is coupled into the optical fiber with a lens, and the output with good beam quality is obtained from the end of the optical fiber. However, with the increase of the output power of the semiconductor laser, the energy density at the output end of the fiber increases a lot, and it is easy to burn out the end face of the fiber connector, resulting in a decrease in output power and poor beam quality. At the same time, in recent years, short-wavelength semiconductor lasers such as green light and blue light have been greatly developed. Due to the high absorption efficiency of optical fiber materials for short wavelengths, it is also easy to damage the fiber joints of such semi-fiber-coupled semiconductor lasers. At the same time, since the fiber-coupled semiconductor laser cannot directly take light at the output end for closed-loop power control, it can only operate in the current mode, or use the internal photodiode of the semiconductor laser for control. However, the internal photodiode of the semiconductor laser can only reflect the power change of the light source and cannot reflect the power change of the fiber output end, so the power stability is poor.

Utility model content

In view of the above-mentioned defects in the prior art, the purpose of this utility model is to propose a free space output semiconductor laser with high beam quality, high stability and long life.

The purpose of this utility model will be achieved through the following technical solutions:

A semiconductor laser, comprising a base, the base is provided with a main light source, a temperature control system, an optical shaping system and a power control system; the main light source is a fiber-coupled semiconductor laser; the temperature control system includes a semiconductor refrigerator, The temperature sensor, temperature control circuit and heat sink cooling system keep the semiconductor laser element working within the set temperature range. The optical shaping system is a collimating lens, through which the fiber-coupled semiconductor laser converts the output of the fiber into a free-space output, and obtains the designed beam quality. The power control system includes a beam splitter, a photodiode and a feedback control system, the fiber-coupled semiconductor laser is fixed on the cold surface of the semiconductor refrigerator, and the hot surface of the semiconductor refrigerator is connected to the base; the The fiber output end of the fiber-coupled semiconductor laser is equipped with an end cap; the end cap is connected with the collimating lens; the collimating lens is fixed on a V-shaped groove, and the output optical path of the collimating lens is provided with The beam splitter is equipped with a photodiode on the beam splitting optical path of the beam splitter, and the photogenerated current of the photodiode is used as a control signal and connected to the feedback control system. The beam splitter divides light from the main beam according to a fixed ratio, and the beam is attenuated to meet the linear input range of the photodiode through the light-taking system and input into the photodiode. The photodiode converts the optical signal into an electrical signal, and the electrical signal is used as a control signal. Drive the driving current of the circuit board, thereby controlling the output power of the semiconductor laser to be stable.

Preferably, the above-mentioned semiconductor laser, wherein: the length of the end cap is 0.5 mm, the contact surface of the end cap is welded to the optical fiber, the outer cladding of the end cap is the same as that of the optical fiber, and the diameter of the core of the end cap is is 0.105mm. When the light is transmitted through the end cap, its beam will diverge. When it reaches the output end of the end cap, the optical power density on the end face will be reduced, so as to ensure that the output end of the fiber will not be burned out and prolong the service life of the laser.

Preferably, the above-mentioned semiconductor laser, wherein: the fiber-coupled semiconductor laser includes a semiconductor laser element, the semiconductor laser element is fixed in a mechanical part, and a coupling lens is installed at the rear of the mechanical part, and the semiconductor laser The free-space output of the component output is coupled into an optical fiber. The mechanical parts have a certain heat capacity and are fixed on the cold surface of the semiconductor refrigerator.

Preferably, the above-mentioned semiconductor laser, wherein: the output end of the fiber-coupled semiconductor laser is coated with an antireflection and anti-reflection coating. The anti-reflection anti-reflection coating can increase the output efficiency of the fiber to the output end, reduce reflection, and at the same time reduce the energy density from the output end face of the fiber core to the fiber connector, thereby protecting the fiber core from being burned.

Preferably, the above-mentioned semiconductor laser, wherein: the photodiode is equipped with an attenuation sheet to ensure that the photoelectric response of the photodiode is in a linear range.

Preferably, the above-mentioned semiconductor laser, wherein: the optical fiber is coiled on the base.

The outstanding effects of the utility model are: the utility model provides a free-space output semiconductor laser with high beam quality, high stability, and long life, which is composed of a temperature control system, a main light source, an optical shaping system and a power control system, so that the main light source The semiconductor laser component outputs laser light at the set temperature, and forms a fiber-coupled semiconductor laser through coupling. Through the optical shaping system, the poor beam of the diode laser is shaped into a high-quality beam output, and the sampling signal is generated by a spectroscope to detect the output power. Changes, and form a closed-loop negative feedback control system with the drive current of the main drive board, so that the output power of the laser can reach high stability. An end cap is installed at the output end of the fiber, which can protect the fiber head from being burned out and prolong the use of the laser. life. The utility model has the characteristics of small size, light weight and low cost at the same time.

The specific implementation of the utility model will be described in further detail below in conjunction with the accompanying drawings of the embodiments, so as to make the technical solution of the utility model easier to understand and grasp.

Description of drawings

Fig. 1 is the structural representation of the semiconductor laser of the utility model embodiment 1;

Fig. 2 is the schematic structural view of the end cap of the semiconductor laser of the utility model embodiment 1;

Fig. 3 is a working schematic diagram of the power control system of the semiconductor laser in Embodiment 1 of the present utility model.

Detailed ways

Example 1

A kind of semiconductor laser of the present embodiment, as shown in Figure 1 and Figure 2, comprises a base 1, is provided with main light source, temperature control system, optical shaping system and power control system on base 1; Main light source is fiber-coupled semiconductor laser , the fiber-coupled semiconductor laser comprises a semiconductor laser element 2, the semiconductor laser element 2 is fixed in a mechanical part 3, and a coupling lens is installed at the rear of the mechanical part 3, and the free space output of the semiconductor laser element 2 is coupled into an optical fiber. The temperature control system includes a semiconductor refrigerator 4, a temperature sensor, a temperature control circuit and a heat sink cooling system to keep the semiconductor laser element 2 working within a set temperature range. The optical shaping system is a collimating lens 5, through which the fiber-coupled semiconductor laser converts the output of the fiber into a free-space output, and obtains the designed beam quality. The power control system includes a beam splitter 6 , a photodiode 7 and a feedback control system 8 . The mechanical part 3 has a certain heat capacity and is fixed on the cold surface of the semiconductor refrigerator 4, and the hot surface of the semiconductor refrigerator 4 is connected to the base 1; the optical fiber is coiled on the base 1. The fiber output end of the fiber-coupled semiconductor laser is equipped with an end cap 9; the length of the end cap 9 is 0.5mm, the contact surface 91 of the end cap 9 is welded with the optical fiber 92, the outer cladding 93 of the end cap 9 is the same as the optical fiber, and the core of the end cap The diameter is 0.105mm. During the transmission process of the end cap 9, the light beam will diverge, and when it reaches the output end 94 of the end cap 9, the optical power density on the end face will be reduced, thereby ensuring that the output end of the optical fiber will not be burned out, and prolonging the service life of the laser . The output end of the fiber-coupled semiconductor laser is coated with anti-reflection and anti-reflection coating. The anti-reflection anti-reflection coating can increase the output efficiency of the fiber to the output end, reduce reflection, and at the same time reduce the energy density from the output end face of the fiber core to the fiber connector, thereby protecting the fiber core from being burned. End cap 9 is connected with collimator lens 5; Collimator lens 5 is fixed on a V-shaped groove, is provided with beam splitter 6 on the output light path of collimator lens 5, and photodiode 7 is installed on the beam splitter light path of beam splitter 6, The photogenerated current of the photodiode 7 is used as a control signal and connected to the feedback control system 8 . The beam splitter 6 splits light from the main beam according to a fixed ratio, and the light beam is attenuated to meet the linear input range of the photodiode 7 through the light-taking system and input into the photodiode 7. The photodiode 7 converts the optical signal into an electrical signal, and the electrical signal As a control signal, the drive current of the drive circuit board is controlled, thereby controlling the output power of the semiconductor laser to be stable. The photodiode 7 is equipped with an attenuation sheet to ensure that the photoelectric response of the photodiode 7 is in a linear range.

The working principle of this embodiment is: after the semiconductor laser element 2 is energized, the semiconductor cooler 4 works, by controlling the current flow direction of the semiconductor cooler 4, the operating temperature of the semiconductor laser element 2 is controlled, thereby ensuring that the semiconductor laser element 2 is at a stable temperature Down working, at the same time, the heat generated when the semiconductor laser element 2 is working is directed from the laser base plate 1 to the external heat sink through the heat sink cooling system. When the temperature sensor detects that the temperature reaches the working temperature, the temperature control circuit supplies the semiconductor laser element 2 with working current. The semiconductor laser element 2 outputs laser light, and through the coupling lens, the free space output is coupled into the optical fiber. At the output end of the optical fiber, the beam output from the optical fiber is shaped into a required beam quality through the collimating lens 5 . The beam splitter 6 on the output light path will reflect the light into the photodiode 7 in proportion. According to the intensity of the output power, adjust the attenuation plate in front of the photodiode 7, so that the photoelectric response of the photodiode 7 is in the linear range: the input light cannot be too strong to make the response of the photodiode 7 enter the saturation region, nor can it be too weak to make the photoelectric current and the photoelectric The dark current of diode 7 is indistinguishable. The light-generated current is used as a control signal, and forms a closed-loop negative feedback control system with the driving current of the main circuit board. Its working process is shown in Figure 3. The beam splitter 6 reflects the output light in proportion and enters the photodiode 7. The photodiode 7 converts the feedback light signal into a current signal. This signal is used as a feedback control signal. The main drive current and Subtracting each other to form a net control current and control output power: when the output power is greater than the set power, its feedback current increases, and after being subtracted by the main drive current, the net control current becomes smaller and the output power becomes smaller; but the output power is less than When the power is set, the feedback current decreases, and after being subtracted by the main drive current, the net control current becomes larger and the output power becomes larger. The closed-loop negative feedback system keeps the output power in a dynamic balance and achieves a highly stable output.

This embodiment provides a free-space output semiconductor laser with high beam quality, high stability, and long life, and has the characteristics of small size, light weight, and low cost.

The utility model still has multiple implementation modes, and all technical solutions formed by equivalent transformation or equivalent transformation all fall within the protection scope of the utility model. the

Claims (6)

1. a semiconductor laser comprises a base, and said base is provided with main light source, temperature control system, optical shaping system and power control system; Said main light source is a fiber coupled laser diode; Said temperature control system comprises semiconductor cooler, temperature sensor, temperature-control circuit and heat sink cooling system; Said optical shaping system is a collimating lens; Said power control system comprises spectroscope, photodiode and feedback control system, it is characterized in that: said fiber coupled laser diode is fixed on the huyashi-chuuka (cold chinese-style noodles) of said semiconductor cooler, and the hot side of said semiconductor cooler is connected with said base; The fiber-optic output of said fiber coupled laser diode is equipped with end cap; Said end cap is connected with said collimating lens; Said collimating lens is fixed on the V-type groove; On the output light path of said collimating lens, be provided with said spectroscope; On said spectroscopical beam split light path, adorn photodiode, the photogenerated current of said photodiode inserts said feedback control system as control signal.

2. semiconductor laser according to claim 1 is characterized in that: said end cap length is 0.5mm, the contact-making surface of said end cap and fused fiber splice, and the surrounding layer of said end cap is identical with optical fiber, and the diameter of the fibre core of said end cap is 0.105mm.

3. semiconductor laser according to claim 1; It is characterized in that: said fiber coupled laser diode comprises semiconductor laser component; Said semiconductor laser component is fixed in the mechanical parts; And coupled lens being housed at the rear portion of said mechanical parts, said mechanical parts is fixed on the huyashi-chuuka (cold chinese-style noodles) of semiconductor cooler.

4. semiconductor laser according to claim 1 is characterized in that: the output of said fiber coupled laser diode is coated with the antireflection anti-reflection film.

5. semiconductor laser according to claim 1 is characterized in that: said photodiode adds attenuator.

6. semiconductor laser according to claim 1 is characterized in that: said fiber reel is on said base.

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